1. Field of the Invention
The present invention relates to a manufacturing method for a sintered body with a buried metallic member that may be used for semiconductor manufacturing apparatus or the like.
2. Description of the Related Art
Currently, semiconductor manufacturing apparatus such as a heater, which heats a semiconductor wafer, an electrostatic chuck, which adsorbs and holds the semiconductor wafer, or a susceptor, which is applied a high-frequency voltage, is used in a semiconductor manufacturing process. Dense ceramics such as aluminum nitride, silicon nitride or alumina are noticeable as base materials for such semiconductor manufacturing apparatus.
With the electrostatic chuck, keeping fluctuation in depth of electrostatic chuck electrodes in a ceramic base plate (i.e., difference between the maximum and the minimum depth, which is hereafter referred to as ‘evenness’) to a minimum is desired. When there is fluctuation in spacing between a chucking surface of an insulative dielectric layer and the electrostatic chuck electrodes, fluctuation in chucking force of the semiconductor wafer on the chucking surface occurs.
In addition, for example, when electrode for plasma generation in the ceramic base plate is slanted with respect to the surface of the ceramic base plate, fluctuation in plasma generation occurs, which adversely affects film formation, and thus fluctuation in film formation occurs. As such, there is demand for securing evenness of metallic member such as electrode in various ceramic members in which the metallic member is buried.
A manufacturing method for a ceramic member, which is made by forming a metallic member on a relatively thin first compact and forming a relatively thick second compact on that metallic member, is disclosed as a technology for improving evenness (e.g., see Japanese Patent Application Laid-open No. Hei 10-249843).
However, very excellent evenness has been recently desired. With the conventional manufacturing method, there are ceramic powders on both surfaces of the metallic member. Consequently, shrinkage is great due to deformation at the time of forming the compact and at the time of sintering, namely densification of the compact. As a result, it is difficult to fulfill the recently desired strict accuracy for evenness.